Inductor structure



Jan. 24, 1956 R. L REID ET AL 2,732,529

INDUCTOR STRUCTURE Filed April 21. 1.948

gvwe/Mmd. FUBEQT LIE'EIEI,

LJU H N LAB A N Emma-,5 EARE'HENBPUNN @ME-MALEEIERT EELAYT/JN UnitedStates Patent INDUCTOR STRUCTURE Robert L. Reid, Indianapolis, Ind.,John Laban, Grass Lake, Mich., George E. Archenbronn, Galeta, Calili,and Albert E. Slayton, Jackson, Mich., assignors to Radio TelevisionProducts Corporation, Grass Lake, Mich., a corporation of MichiganApplication April 21, 1948, Serial No. 22,408

'8 Claims. Cl. 333-78 The present invention relates to structuralimprovements in the manufacture of inductors used in radio receivers andthe like.

It is an object of the invention to provide an inductor structure whichis electrically and mechanically stable under "all normal operatingconditions yet may be economically.manufactured.

Another object is to provide an improved inductor of the typev describedin which the terminal members constitute the main structural elements ofthe frame.

Another object is to provide an improved inductor construction of thetype described having structural frame member serving in the pluralcapacity of terminals, structural tie rod, and spring contactor for thecoil tuning capacitors.

A further object of the invention is to provide an in expensive yeteffective means of holding part of the case structure against rotationand provide an elastic nut element for the adjustment screw for thecores within the coils.

These and other objects and advantages residing in the construction,arrangement, and combination of parts will more fully appear from thefollowing specification and the appended claims:

In the drawings,

Fig. I is a side elevational view of the assembled inductor unit,

Fig. II is similar to Fig. I with the metallic shielding housingremoved,

Fig. III is a vertical cross section view taken on line IIIIII of Fig.II,

-- Fig. IV is a section taken on line IVIV of Fig. III,

Fig. V is a perspective view of the structural terminal element,

Fig. VI is a perspective view of the insulating end blocks,

Fig. VH is an enlargement of a detail of construction,

Fig. VIII is a vertical sectional view of Fig. I,

Fig. IX is a view similar to'Fig. I of a modified construction, and

Fig. X shows the terminal of Fig. IX applied to the assembly.

Referring to the drawings, in Fig. I the inductor unit comprises ametallic shielding housing 12 closed at the top except for an apertureto provide clearance for the adjustment screw 14 and open at bottom topermit the structure of Fig. II to be inserted with a slip fit betweenthe inside of the housing 12 and the insulating end members 16 and 18.Tabs 20 are turned under as shown in Fig. I to engage the underside ofthe end member 18 to hold the parts assembled.

To describe the inductor unit, the end members 16 and 18 may beidentically molded parts of suitable insulating material. T-slots 20 areprovided to receive the terminal tie rods 22 which are preferably formedof resilient metal. As shown in Fig. V, the rod 22 has an upper contactend 24 which is bent to form a slightly acute angle with thelongitudinal portion 26, the purpose of which will be described later.As shown the portion 26 of each rod 22 has deformable tabs 28 and 30lanced out of the body of the portion with the end of each rod 22 formedinto a terminal portion 32.

As more clearly shown in Figs. III, IV and V, the end members 16 and 18are molded with a rim 34, which with the separators 36 define spaces 38in which the contact ends 24 of opposed rods 22 overlap each other butseparated by the silver mica capacitors 40. The contact ends 24 in theassembly of Fig. III are shown at to the portions 26 of the rods 22which results in a stress stable engagement between the ends 24 and thecapacitors 40 for the reason that the ends 24 as shown in Fig. V areremoved from an acute angleto the portions 26 in an unstressed state.

The transverse wall 42 of the members 16 and 18 is shown with similarrecesses 44 upon opposite sides thereof in the form of cylindricalportions 46 into which elongated lateral portions 48 open. Thecylindrical portions 46 are provided to receive the opposite ends of theinsulating core sleeve 50, preferably fabricated from relatively stiffyet deformable fibre stock. Prior to inserting the ends 52 of the sleeve50 into the recesses 44, tension and ground members 53 and 53' ofresilient wire have transverse portions 54 which are placed in therecesses 44 to be positioned adjacent the apertures 56 through which theadjustment screws 58 extend. The screws 58 carry the iron cores 60adjustably located within the coils 62 mounted upon the sleeve 50.

In assembling the component parts shown in Fig. III, the sleeve 50 actsto space the end members 16 and 18. With the sleeve 50 in place, therods 22 are threaded through the T-slots 20 of the ends 16 and 18 andtensioned to bring the ends 24 down as shown in Fig. III at the sametime, the tabs 30 sp ing out to engage the under side of the projection64. The parts are now rigidly held together with sufficient tension toembed the portions 54 into the ends of the fibre sleeve 50 to hold thesame against rotation relative to the ends 16 and 18.

In addition to locking the sleeve 50, the portions 54 are stressed intothe threads of the screws 58 to hold the screws against axial movementexcept upon rotation. Thus it will be understood that the portions 54enable the screws to be inserted in the apertures 56 and forced past theportions 54 without rotation yet provide fine adjust ment of the cores60 upon rotation of the screws 58. As more clearly shown in Figs. II andVIII the members 53 and 53' project beyond the sides of the ends 16 and18 to resiliently engage the inside of the housing 12 to ground each ofthe cores 60 of the rods 22. Insertion of the structure of Figs. II andIII completes the assembly of the unit of Fig. I. It will be understoodthat the terminal tie rods 22 function as conductive bus bars in thecompleted unit and provide the connection terminal portions.

To assemble the unit shown in Fig. III, the rods 22 are inserted intothe slot 20 and the required number of silver mica capacitors areinserted between the overlapping ends 24 of the rods 22 disposed in thespaces 38 of the end 16. With the rods 22 untensioned the ends 24 willassume the positions shown in Fig. VII. The core sleeve 50 and itscomponent parts are then brought into the unit assembly by inserting theadjustment screw 58, at the upper end, into the aperture 56 in the end16, the wires 54 racketing over the threads until the end 52 of thesleeve 50 is disposed in the recess 44. Next, the rods 22 are threadedthrough the slots 20 of the lower end 18 and the lower screw 58 isprojected through the aperture 56 until the lower end of the tube 50 isdisposed in the recess 44. The rods 22 are now tensioned to stressthe-ends. 24 into the position shown in Fig. III and the tabs 30 whichare resilient spring outwardly after travers- 3 ing the slots 20 toengage beneath the projections 64. The terminals es of the coils 62 arethen soldered to the tabs 68. To compensate for the overlap on oppositesides of the condensers do to the rods 22 below the condensers areslightly shorter in overall length.

In Fig. IX is shown a slight modification of the terminal tie rod 22 ofFig. V. As shown, the terminal rod 70 has deformable tabs 72 and 74spaced from the contact end 76 as to be bent out at right angles toengage with the under side of the projection 64' of the end members 16and 18'. In the assembly of Fig. X, it will be understood that the tab72 holds the contact 76 in fixed stressed position independently of thespacing action of the sleeve 50 or the tensioning of the members 116'and 13 by the terminal tie rods 22. As more clearly shown in Fig. IX,swallow tail tabs 78 assist in the attachment of the ends of the coils62.

Having thus described our invention, what we claim as new and desire toprotect by Letters Patent is:

1 An inductor unit comprising a pair of end members, opposed centrallylocated recesses in said end members, a fiber tubular spacing memberhaving its ends telescoping in said opposed recesses, a coil supportedupon the outside of said tubular member, a tuning core for said coillocated within said tubular member, a longitudinally extending threadedadjustment member for said core, an aperture opening through one of saidrecesses through which said adjustment member extends, a spring wiresupported on one of said end members in bridging relation to said recessagainst which one end of said tubular member abuts to partially imbedsaid wire therein, said spring member being disposed to one side of saidaperture and having tangential engagement with the thread of saidmember.

2. An inductor unit comprising an end member, a tubular coil supportingmember of deformable material, a core supported in said supportingmember, a spring wire disposed across one end of said tubular member andpartially imbedded therein, an adjustment screw connected to said coreand extending through said end member, a portion of said spring wirehaving tangential stressed engagement with the threads of saidadjustment screw to act as a nut, a metallic housing for said endmember, one portion of said spring wire extending into groundingengagement with said housing.

3. An inductor unit comprising a pair of molded end parts of insulatingmaterial, a centrally located longitudinally extended tubular memberdisposed between said parts, recesses defined in the opposed faces ofsaid parts in which the ends of said member are telescopically received.slots defined in opposed sides of each end part in axial alignmentwiththe slots of the associated end part, longitudinally extendingconductive tie rods of flat stock closely fitted in the axially alignedslots of said parts, said rods having integral projections thereondeflected into overlapping arrangement with said end parts to clamp saidmember between said end parts, said rods having connection-terminalportions extending beyond one of said end parts and said deflectedportion associated therewith.

4. An inductive unit comprising a molded part of insulating material, acentrally located longitudinally extending member supported upon saidpart, a recess defined in a face of said part in which one end of saidmember is telescopically received, slots defined in opposite sides ofsaid part, longitudinally extending conductive rods of fiat stockclosely fitted in said slots, said rods having integral projectionsthereof deflected into overlapping arrangement with said part torestrain said rods against movement in said slots, condensers supportedon a face of said part, certain of said integral projections beingdisposed in conductive contact with said condensers, other of saidintegral projections engaging with said part to maintain said conductivecontact, said rods having portions constituting connection terminalsremoved from said part, said other ti projections being located on saidrods between said terminals and said part.

5. An inductor unit comprising a pair of end members, a centrallylocated longitudinally extending member spacing said end members,longitudinally extending conductive tie rods of flat stock for drawingsaid end members toward each other to piace said spacing member undercompression, axially aligned slots in said end members in which saidrods are closely fitted to hold said tie rods against rotation and saidend rods in rigid angular relationship with each other, there beingintegral portions of said rods extending beyond said end members anddeflected into overlapping stressed engagement with end face portionsthereof to hold the component parts of the unit in assembly, condensersmounted upon the end face of one of said end members and disposedbetween the overlapping deflected portions of said rods associatedtherewith with the stressed engagement of certain of said rods with saidend member being through said condensers.

6. An inductor unit comprising an end member, a tubular coil supportingmember of deformable material, a core supported in said coil supportingmember, a spring wire disposed across one end of said tubular member andpartially imbeddedtherein, an adjustment screw connected to said coreand extending through said end member, a portion of said spring wirehaving tangential stressed engagement with the threads of saidadjustment screw to act as a nut.

7. An inductor unit comprising a member having an unthreaded smooth boreopening defined therein, a tubular coil supporting member axiallyaligned with said opening, a length of spring wire disposed across saidopening with the ends of said wire afiixcd to said first member tosupport the same against lateral displacement, a core supported in saidcoil supporting member, an adjustment screw connected to said core andextending through said smooth bore opening, a portion of said springwire between the ends thereof being deflected by and having tangentialstressed engagement with the threads of said adjustment screw to act asa nut therefor, said wire constituting the sole means in cooperationwith said threads for axially moving said screw relative to said firstmember upon rotation of said screw as well as constituting a lockingmeans for said screw against unintentional rotation.

8. An inductive unit comprising a molded part of insulating material, acentraliy located longitudinally extending member supported upon saidpart, a recess defined in a face of said part in which one end of saidmember is telescopically received, slots defined in opposite sides ofsaid part, longitudinally extending conductive rods of fiat stockclosely fitted in said slots, said rods having integral projectionsthereof deflected into overlapping arrangement with said part torestrain said rods against movement in said slots, certain of saidintegral projections being disposed on one side of said part, other ofsaid integral projections engaging with an opposite side of said part,said rods having portions constituting connection terminals removed fromsaid part, said other projections being located on said rods betweensaid terminals and said part.

